[Bug fix] KNN brute force is not working anymore when an index exists (#4143)

core/src/idx/planner/tree.rs

@@ -338,9 +338,10 @@ impl<'a> TreeBuilder<'a> {
 						local_irs,
 						remote_irs,
 					)?;
-				} else if let Some(id) = left.is_non_indexed_field() {
+				}
+				if let Some(id) = left.is_field() {
 					self.eval_bruteforce_knn(id, &right, &exp)?;
-				} else if let Some(id) = right.is_non_indexed_field() {
+				} else if let Some(id) = right.is_field() {
 					self.eval_bruteforce_knn(id, &left, &exp)?;
 				}
 				let re = ResolvedExpression {
@@ -591,11 +592,12 @@ impl Node {
 		}
 	}
 
-	pub(super) fn is_non_indexed_field(&self) -> Option<&Idiom> {
-		if let Node::NonIndexedField(id) = self {
-			Some(id)
-		} else {
-			None
+	pub(super) fn is_field(&self) -> Option<&Idiom> {
+		match self {
+			Node::IndexedField(id, _) => Some(id),
+			Node::RecordField(id, _) => Some(id),
+			Node::NonIndexedField(id) => Some(id),
+			_ => None,
 		}
 	}
 }

core/src/idx/trees/hnsw/mod.rs

@@ -260,14 +260,13 @@ where
 						unreachable!()
 					}
 				}
-				Some((ep_dist, ep_id))
+				return Some((ep_dist, ep_id));
 			} else {
 				#[cfg(debug_assertions)]
 				unreachable!()
 			}
-		} else {
-			None
 		}
+		None
 	}
 
 	fn get_vector(&self, e_id: &ElementId) -> Option<&SharedVector> {

lib/tests/vector.rs

@@ -1,6 +1,6 @@
 mod helpers;
 mod parse;
-use crate::helpers::{new_ds, skip_ok};
+use crate::helpers::{new_ds, skip_ok, Test};
 use parse::Parse;
 use surrealdb::dbs::Session;
 use surrealdb::err::Error;
@@ -225,18 +225,14 @@ async fn select_where_hnsw_knn() -> Result<(), Error> {
 		DEFINE INDEX hnsw_pts ON pts FIELDS point HNSW DIMENSION 4 DIST EUCLIDEAN TYPE F32 EFC 500 M 12;
 		LET $pt = [2,3,4,5];
 		SELECT id, vector::distance::knn() AS dist FROM pts WHERE point <|2,100|> $pt;
-		SELECT id FROM pts WHERE point <|2,100|> $pt EXPLAIN;
+		SELECT id, vector::distance::knn() AS dist FROM pts WHERE point <|2,100|> $pt EXPLAIN;
+		SELECT id, vector::distance::knn() AS dist FROM pts WHERE point <|2,EUCLIDEAN|> $pt;
+		SELECT id, vector::distance::knn() AS dist FROM pts WHERE point <|2,EUCLIDEAN|> $pt EXPLAIN;
 	";
-	let dbs = new_ds().await?;
-	let ses = Session::owner().with_ns("test").with_db("test");
-	let res = &mut dbs.execute(sql, &ses, None).await?;
-	assert_eq!(res.len(), 7);
-	//
-	for _ in 0..5 {
-		let _ = res.remove(0).result?;
-	}
-	let tmp = res.remove(0).result?;
-	let val = Value::parse(
+	let mut t = Test::try_new(sql).await?;
+	t.skip_ok(5);
+	// KNN result with HNSW index
+	t.expect_val(
 		"[
 			{
 				id: pts:1,
@@ -248,9 +244,8 @@ async fn select_where_hnsw_knn() -> Result<(), Error> {
 			}
 		]",
 	);
-	assert_eq!(format!("{:#}", tmp), format!("{:#}", val));
-	let tmp = res.remove(0).result?;
-	let val = Value::parse(
+	// Explains KNN with HNSW index
+	t.expect_val(
 		"[
 					{
 						detail: {
@@ -271,7 +266,42 @@ async fn select_where_hnsw_knn() -> Result<(), Error> {
 					}
 			]",
 	);
-	assert_eq!(format!("{:#}", tmp), format!("{:#}", val));
+	// KNN result with brute force
+	t.expect_val(
+		"[
+			{
+				id: pts:1,
+				dist: 2f
+			},
+			{
+				id: pts:2,
+				dist: 4f
+			}
+		]",
+	);
+	// Explain KNN with brute force
+	t.expect_val(
+		"[
+				{
+					detail: {
+						table: 'pts'
+					},
+					operation: 'Iterate Table'
+				},
+				{
+					detail: {
+						reason: 'NO INDEX FOUND'
+					},
+					operation: 'Fallback'
+				},
+				{
+					detail: {
+						type: 'Memory'
+					},
+					operation: 'Collector'
+				}
+			]",
+	);
 	Ok(())
 }